1. Field of Art
The disclosure generally relates to the field of prosthetic heart valves, and more specifically to trileaflet mechanical prosthetic heart valves.
2. Description of the Related Art
When one of the valves inside a patient's heart does not work properly, the heart valve may be replaced with a prosthetic valve. Heart valve diseases may be classified into two different categories: regurgitation and stenosis. Regurgitation, or backflow, occurs if a valve doesn't close tightly. Blood leaks back into the chambers rather than flowing forward through the heart or into an artery. Stenosis occurs if the flaps of a valve thicken, stiffen, or fuse together. This prevents the heart valve from fully opening. As a result, not enough blood flows through the valve.
Prosthetic heart valves can be categorized into two main categories: mechanical prosthetic heart valves, and tissue or bio-prosthetic heart valves. Mechanical prosthetic heart valves are durable and may last throughout the remainder of the patient's lifetime. Currently existing mechanical prosthetic heart valves do not mimic a human natural heart valve shape. Even in the fully opened position, leaflets may partially block the passage of blood through the valve causing turbulence in the blood. The increased turbulence in the blood increases the probability of coagulation of the blood near the regions of high turbulence around the mechanical prosthetic heart valve. Patients with mechanical prosthetic heart valves oftentimes take anticoagulants and/or blood thinners to prevent blood clots from forming and causing a malfunction of the mechanical prosthetic heart valve and/or turning into an embolism. In addition, the opening and closing of the leaflets causes wear and tear near the interface between the leaflets and the hinges to which the leaflets are attached. The leaflets may also be susceptible to being stuck in the opened position if the leaflets open past a threshold angle which causes the backwards blood flow to push the leaflets on the wrong side, holding the leaflets in the opened position instead of pushing the leaflets to rotate to the closed position.
Tissue valves are made from valves of an animal donor or another animal tissue that is strong and flexible. Tissue valves can last 10 to 20 years and patients with prosthetic tissue heart valves do not need to take anticoagulants or blood thinners. The likelihood of a prosthetic tissue heart valve to malfunction later in the patient's life due to wear and tear is higher than of mechanical prosthetic heart valves, and thus, patients with prosthetic tissue heart valves may additionally have a second heart surgery to replace the prosthetic tissue heart valve.